Mother's pain in knee. Anything serious?

Few months back my mother was operated for gall bladder removal due to stones in it. Since her discharge from the hospital, she has been complaining of complete numbness in her right thigh from knee upwards. I had also seen red spots on hér thighs after the operation probably due to blood clots due to her sleeping on one side during her recovery in the hospital. Also she has developed pain in her knees specially after prolonged duration of sitting with bend knees.this pain was not present before the operation.she complains of pain while trying to sit down or get up from the ground level.it seams somethings related to her nerves may be.which doctor should i refer. A neurologist or a phsiotherapist??can it be anything serious?? Plz advice. Thank you.